A study indicates that factory-farmed chicken has caused over a 100-fold increase in Campylobacter, a prevalent food poisoning disease. Researchers discovered that industrial farming, especially densely populated chicken flocks, enables Campylobacter strains from wild birds to intermingle and become established within commercial poultry populations. Campylobacter is the leading bacterial cause of diarrhoea worldwide, and growing antimicrobial resistance is making these infections progressively harder to treat. The study, which analysed almost 2,800 bacterial genomes from chickens and wild birds in 30 countries between 1979 and 2024, highlights how the global expansion of chicken farming creates optimal conditions for the bacterium's spread. Scientists propose that extensive, densely populated chicken flocks function as 'pathogen sponges,' absorbing and amplifying bacterial strains, with modelling showing these strains can become self-sustaining once chicken populations reach a critical size. In fullFactory farming could be fuelling spread of common disease which causes food poisoning